conductor size

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ss electric1

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How do you determine Conductor size?
example: 125 Amp. a-b-n-grd.
310.15 B 16 / 60 deg. or 90 deg.
310.15 B / Temperature at connection
Circuit Breaker lug rating?
Thanks for info.
 
Conductor size is based on many parts. Obviously the temp of the wire and the terminal is one part. The size may be influenced by the number of conductors in a raceway- de-rating would come into play.

What specifically are you trying to figure out
 
Dennis Alwon said:
Conductor size is based on many parts. Obviously the temp of the wire and the terminal is one part. The size may be influenced by the number of conductors in a raceway- de-rating would come into play.

What specifically are you trying to figure out
Click to expand...

125 amp 120/240 volt 1 phase.
30 foot, 2 hot / 1 neutral / 1 ground.
does 310.15 B state that you use terminal temperature rating to size conductor?
#3 for 90 deg. or #1/0 for 60 deg.
 
ss electric1 said:
125 amp 120/240 volt 1 phase.
30 foot, 2 hot / 1 neutral / 1 ground.
does 310.15 B state that you use terminal temperature rating to size conductor?
#3 for 90 deg. or #1/0 for 60 deg.
Click to expand...

HOw about #1 for 75? ? :D
As HEYDOG suggest, go to 110.14 to determine which rating you can terminate.
Then check the type condutcor you are using and check it's rating (THHN=90, NM=60, etc.}
Apply derating factors as needed (conduit fill, ambient)
Recheck against 110.14
125 amp would "normally" be a #1 THHN, 1/0 NM or SE under certain condtions or a #2 if its a "whole house service or main feeder"
Lots to take into account as Dennis states.
 
augie47 said:
HOw about #1 for 75? ? :D
As HEYDOG suggest, go to 110.14 to determine which rating you can terminate.
Then check the type condutcor you are using and check it's rating (THHN=90, NM=60, etc.}
Apply derating factors as needed (conduit fill, ambient)
Recheck against 110.14
125 amp would "normally" be a #1 THHN, 1/0 NM or SE under certain condtions or a #2 if its a "whole house service or main feeder"
Lots to take into account as Dennis states.
Click to expand...

#1 THHN seems to be correct.
thanks
 
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